This wasn’t intended to be a dig against vault holders, or to prejudice the governance process towards providing less compensation. The main purpose of stating this is to try to avoid legal problems with the current situation and set expectations that compensation will not be provided for any events that might occur in the future.
Vault owners have rights and responsibilities which are written into Maker’s source code and described in the docs (e.g. vault owners can withdraw collateral over their required liquidation ratio at any time, but they are also responsible for maintaining sufficient collateral). However, if vaults are liquidated, there is no guarantee made of receiving any collateral back as this depends on the auction price.
The liquidation process may not have been understood by some users, but MakerDAO and MKR holders only control the core protocol and not any user interfaces. Without control, they can’t take on responsibility for disclosures on websites that offer vault creation.